System and method of determining standby time for mobile stations

ABSTRACT

A method and system for determining standby time for a mobile station uses a battery simulator, a base station emulator, a computer to control the test equipment and MSUT for testing a mobile station. The computer includes a module for determining a radio off battery voltage, a module for deriving a battery capacity in dependence upon the radio off battery voltage, a module for measuring battery capacity usage in a predetermined time while the mobile station is in standby mode and a module for determining a standby time for the mobile station in dependence upon the battery capacity and the battery capacity usage, where the predetermined time is less than the standby time.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 12/949,229,filed on Nov. 18, 2010, now allowed, which is a continuation ofapplication Ser. No. 12/752,330, filed on Apr. 1, 2010, now U.S. Pat.No. 7,873,393, which is a continuation of application Ser. No.11/494,443 filed on Jul. 28, 2006, now U.S. Pat. No. 7,706,845, which isa non-provisional application claiming the benefit of U.S. ProvisionalApplication No. 60/703,429 filed Jul. 29, 2005, all prior applicationsare hereby incorporated by reference.

This patent document relates generally to testing mobile stations, andin particular to a system and method of determining standby time formobile stations.

BACKGROUND

Mobile station battery life is usually described in terms of talk-timeand standby time. Known methods of measuring standby time for mobilestations require substantial lengths of time to execute. With theproliferation of mobile station models and features, standby timedetermination must be repeated for each new variation, addingconsiderable cost to test protocols. The current method used to teststandby time detailed in a standard by the CDMA Development Group (CDG35) has an extremely long test time which is equal to its standby time,almost 10 days in some cases. The length of these tests makes it nearlyimpracticable to run multiple test cases.

There is a need for a mobile terminal standby test method and apparatusthat reduces test times.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the patent disclosure will now be described by way ofexample only with reference to the following drawings in which:

FIG. 1 there is illustrated an example of a system for determiningstandby time, in accordance with an embodiment of the patent disclosure;

FIG. 2 there is illustrated an example of a four wire setup for a mobilestation under test (MSUT) in accordance with an embodiment of the patentdisclosure;

FIG. 3 graphically illustrates an example of transmit mode currentmeasurement, in accordance with an embodiment of the system fordetermining standby time of the MSUT;

FIG. 4 graphically illustrates an example of receive mode currentmeasurement in accordance with an embodiment of the system fordetermining standby time of the MSUT;

FIG. 5 shows in a flowchart an example of a method of determiningstandby time for mobile stations, in accordance with an embodiment ofthe patent disclosure;

FIG. 6 shows in a flowchart another example of a method of determiningstandby time for mobile stations, in accordance with an embodiment ofthe patent disclosure;

FIG. 7 shows in a flowchart another example of a method of determiningstandby time for mobile stations, in accordance with an embodiment ofthe patent disclosure;

FIG. 8 shows in an execution and variable flow diagram another exampleof a method of determining standby time for mobile stations, inaccordance with an embodiment of the patent disclosure;

FIG. 9 shows in a flowchart an example of a method of determining theradio shut off voltage, in accordance with an embodiment of the patentdisclosure;

FIG. 10 shows in a flowchart another example of the process to determineradio shut off voltage, in accordance with an embodiment of the patentdisclosure;

FIG. 11 shows in a flowchart an example of a method of characterizingtransmit current measurements, in accordance with an embodiment of thepatent disclosure;

FIG. 12 shows in a flowchart another example of a method ofcharacterizing transmit current measurements, in accordance with anembodiment of the patent disclosure;

FIG. 13 shows in a flowchart an example of a method of characterizingreceive current measurements, in accordance with an embodiment of thepatent disclosure; and

FIG. 14 shows in a flowchart another example of a method ofcharacterizing receive current measurements, in accordance with anembodiment of the patent disclosure.

DETAILED DESCRIPTION

The patent disclosure describes a solution to one or more of theproblems described above.

The technology disclosed herein is particularly well suited for use inPersonal Digital Assistants (PDAs), mobile communication devices,cellular phones, and wireless two-way e-mail communication devices(collectively referred to herein as “mobile stations” or “mobiledevices”).

The term “battery capacity” is used to refer to the capacity of abattery. Typically in a mobile terminal environment it is the amount ofdischarge from a fully charged battery, to the mobile terminal batterycut off voltage. The battery cut off voltage is usually the voltage atwhich the mobile terminal shuts down or in some instance where the radiois shut off or disabled. The term “battery capacity consumed” (alsoknown as “charge consumed” or “charge”) is used to refer to the amountof discharge.

In accordance with an embodiment of the patent disclosure, there isprovided a simulated standby time test method that determines a standbytime of a MSUT based on available battery capacity and characterizationof radio shut-off voltage, receive and transmit current measurements,which advantageously considerably cuts down the test time. For mobiledevice where radio is the only function, the radio shut-off voltage isequivalent to mobile device shut-off. For some smart phones or PDAs, theradio will shut-off before the mobile device shuts off, and radioshut-off voltage should be characterized. In this document radioshut-off will be used.

In accordance with another embodiment of the patent disclosure, there isprovided a method of determining standby time for a mobile station. Themethod comprises the steps of for a predetermined time, measuringbattery capacity usage while the mobile station is in standby mode, anddetermining a standby time for the mobile station in dependence upon thebattery capacity and the battery capacity usage, where the predeterminedtime is less than the standby time.

In accordance with another embodiment of the patent disclosure, there isprovided a method of determining standby time for a mobile station. Themethod comprises the steps of for a predetermined time, measuringaverage current consumption while the mobile station is in standby mode,and determining a standby time for the mobile station in dependence uponthe battery capacity and the average current consumption, where thepredetermined time is less than the standby time.

In accordance with another embodiment of the patent disclosure, there isprovided a method of determining standby time for a mobile station. Themethod comprises the steps of determining a radio off battery voltage,deriving a battery capacity in dependence upon the radio off batteryvoltage, for a predetermined time, measuring battery capacity usagewhile the mobile station is in standby mode, and determining a standbytime for the mobile station in dependence upon the battery capacity andthe battery capacity usage, where the predetermined time is less thanthe standby time.

In accordance with another embodiment of the patent disclosure, there isprovided a method of determining standby time for a mobile station. Themethod comprises the steps of determining a radio off battery voltage,deriving a battery capacity in dependence upon the radio off batteryvoltage, for a predetermined time, measuring average current consumptionwhile the mobile station is in standby mode, and determining a standbytime for the mobile station in dependence upon the battery capacity andthe average current consumption, where the predetermined time is lessthan the standby time.

In accordance with another embodiment of the patent disclosure, there isprovided a system for determining standby time for a mobile station. Thesystem comprises a battery simulator, a base station emulator and acomputer including a module for determining a radio off battery voltage,a module for deriving a battery capacity in dependence upon the radiooff battery voltage, a module for measuring battery capacity usage in apredetermined time while the mobile station is in standby mode and amodule for determining a standby time for the mobile station independence upon the battery capacity and the battery capacity usage,where the predetermined time is less than the standby time.

In accordance with another embodiment of the patent disclosure, there isprovided a system for determining standby time for a mobile station. Thesystem comprises a battery simulator, a base station emulator and acomputer including a module for determining a radio off battery voltage,a module for deriving a battery capacity in dependence upon the radiooff battery voltage, a module for measuring current consumption whilethe mobile station is in standby mode and a module for determining astandby time for the mobile station in dependence upon the batterycapacity and average current consumption, where the predetermined timeis less than the standby time.

A system and method of the patent disclosure will now be described withreference to various examples of how the embodiments can best be madeand used. For convenience, like reference numerals are used throughoutthe description and several views of the drawings to indicate like orcorresponding parts, wherein the various elements are not necessarilydrawn to scale. All units of measurement provided in this disclosure areby way of example only. Alternative units of measurement can be usedwith appropriate amendments to the calculations described herein.

This method simulates the standby time of the MSUT. The following methoddescribes the calculations that were used to achieve the results.

Capacity, measured in units of Ampere*hours (Ah), is a standardindication of how long a battery can last. The standby time (hours) of aMSUT can be calculated by dividing the capacity available from a fullycharged battery by the capacity used in one hour (i.e., the amount ofcharge discharged in one hour) with the MSUT in standby.

Referring to FIG. 1 there is illustrated a system 10 for determiningstandby time for a mobile station. Test equipment coupled to a MSUT 12(with its battery removed) includes a base station emulator 14, forexample an Agilent 8960-10 coupled via a radio frequency (RF) cable 16to the MSUT antenna connector, a battery simulator (also known as a“battery simulator power supply”, referred to as a battery simulator inthis description) 18 coupled to the battery contacts of the MSUT 12, forexample an Agilent 66321D, an equivalent series resistance (ESR) isprogrammed in the battery simulator 18 to equate to the ESR value of thebattery used in the MSUT may be used (alternatively a lead having thesame series resistance as the ESR of the mobile battery may be used) anda computer 20 for data collection and/or control.

Referring to FIG. 2 there is shown a four wire setup 21 between thebattery simulator 18 and the MSUT 12. The wire set up includes a pair ofpower lines twisted together 22, each having (undesirable) seriesresistance of the wire 24, and a twister pair of sense lines 26. Themobile battery is removed and the battery simulator 18 is connectedusing the four wire set up 21 so that the battery simulator 18 wouldeffectively compensate for the series resistance 24. If the four wireset up 21 is not used then the external equivalent series resistance(ESR) 24 of the wires connecting to the battery simulator to the devicemust be accounted for in programming the battery ESR value into thebattery simulator 18.

The mobile station RF insertion loss between the MSUT 12 and thewireless device tester (i.e. RF cable AB 16) is measured over a range offrequencies using a network analyzer (not shown). The insertion lossesare then used in this test to correct the settings for the base stationemulator 14 transmit power.

For any given battery voltage, the remaining battery capacity or chargecan be determined from tables provided by the battery manufacturer as afunction of unloaded voltage of the battery. (The tables can also bedetermined by discharging a battery with a constant known load whilemeasuring the voltage as a variable over time.) From the tables, thecapacity or charge remaining in a fully charged battery (C_(new)) and adischarged battery (C_(cutoff)) can be determined. The difference is thetotal battery capacity or charge available to the MSUT.

The voltage of a fully charged battery is dependent on the charger inthe MSUT and also on the battery. It can be obtained by measuring thebattery voltage using a voltage meter after a battery is fully chargedby the charger within the MSUT. However, a cut off voltage (i.e., thevoltage at which to turn off the radio by the MSUT) is determined foreach individual test case by stepping down the voltage until the radioturns off. Depending on the MSUT software/hardware implementation, itmay be necessary to increase the wait time between the voltage steps toensure that the MSUT has time to update. For simplifying a test,approximations may also be made by only testing one or a fewrepresentative test conditions for the cut-off voltage, e.g., using themaximum transmit power condition in a traffic channel transmittingstate, rather than testing for each individual conditions such as idlestate, registration state, traffic channel transmitting state, etc.Although traffic transmitting state is not used in usual stand-byconditions, since it is easy to configure and simplifies the test, itcan be used to simulate the registration condition with certain degreeof accuracy. (Traffic channel and max Tx power condition can be used asa way of approximation).

There are two modes in standby: Receive and Transmit. For the most partthe MSUT 12 is in Receive mode, where it waits to receive messages fromthe network. In this mode, the current draw is quite small. The devicespends most of the time in sleep mode, and wakes up for short period oftime at scheduled time slots to receive messages from base stations. InTransmit mode, the MSUT is required to transmit registration probes atregular intervals as specified by the network. This mode occurs lessfrequently, but draws significantly more current when in that state.

In either mode, the capacity or charge used by the MSUT 12 can bedetermined by measuring the current. Capacity or charge consumed is theintegral of current with respect to time: C=∫i(t) dt. This can bequantized into: C=Σi(t)*Δt. Therefore, the capacity or charge (C) can bedetermined by summing the products of current (i(t)) and time interval(Δt) of current measurement over small intervals, i.e., taking the sumof these measured currents and multiplying the sum by the time interval(Δt). The capacity or charge used by the MSUT 12 in Receive and Transmitmodes is dealt with separately.

In Transmit mode, current measurements are taken for multiple transmitevents to determine the total average capacity or charge used fortransmitting. For the j^(th) transmit event, the capacity or charge usedfor transmitting is C_(j). The total time spent transmitting during thattransmit event, t_(j), is also calculated, as it is needed forcalculations later on. The battery current for each transmit event istaken from the MSUT 12 as a vector of equally spaced sample data points.The sampling interval is, in one example, 4 ms and a total of 4096current measurement data points are downloaded from the batterysimulator 18 for each event which form the vector. The actual transmitportion is extracted from the vector.

In a live network, the MSUT 12 may be configured for timer-basedregistration to transmit at intervals of 15 minutes, 30 minutes, or evenlonger. By using the test procedure described above in the Base StationEmulator 14 this interval can be configured to be shorter to reduce theamount of test time required to achieve a statistically significant dataset of transmit events.

FIG. 3 illustrates an example of a current measurement during Transmitmode, where k represents the data points in the current measurementvector and where Δt represents the sample interval between data pointsin the vector. The element corresponding to k=0 is the first element ofthe extracted sub-array for the transmit activity, and k=m the last. Thebeginning and the end of the sub-array is determined by finding thefirst and the last elements of the measured current array that hashigher current value than receive current of the MSUT during “wake-up”of slotted mode operation.

The equations for the capacity or charge C_(j) and time t_(j) for eachtransmit event are shown here, where the current of the k^(th) point inthe measurement vector is called i_(k):

C _(j)=(Σ_(k=0) ^(m)(i _(k)))*Δt; and

t_(j)=m*Δt.

Using the total number of transmit events measured (N) and the number oftimes the MSUT registers per hour (M) in a network (where in thenetwork, M may or may not be an integer), the total average capacity orcharge used for transmitting in one hour (C_(tx) _(—) _(in) _(—)_(1 hr)) and the total average time spent in one hour for transmitting(t_(tx) _(—) _(in) _(—) _(1 hr)) can be determined:

C _(tx) _(—) _(in) _(—) _(1 hr)=(Σ_(j−1) ^(N) (C _(j)))*(M/N); and

t _(tx) _(—) _(in) _(—) _(1 hr)=(Σ_(j=1) ^(N) (t _(j)))*(M/N).

Referring to FIG. 4, illustrated is an example of a Receive Mode CurrentMeasurement. In Receive mode (including sleep state, processor wake-upactivities, and receiver wake-ups in slotted mode), the current waveformhas a series of peaks that corresponds to intervals of MSUT 12 activity.The peaks of current caused by wakeups appear at known regularintervals, whereas the peaks caused by processor wake-ups can appear atvariable intervals. Each receive measurement is set to capture thecurrent for all receive states including the peaks and base levels, andtakes the average current i_(rx). In one example, the measurementinterval is 1 ms, a total of 4096 values are in each measured vector.

Since the time spent in Receive mode is simply the amount of time notspent in transmitting, using hour as the unit for time, the totalcapacity or charge used by the MSUT during one hour while in Receivemode can be found by:

C _(rx) _(—) _(in) _(—) _(1 hr)(i _(rx)*(1−t _(tx) _(—) _(in) _(—)_(1 hr))).

Alternatively, since the time spent in transmitting access probes fortimer based registration is much smaller than the time spent in Receivemode, the t_(tx) _(—) _(in) _(—1 hr) can be treated approximately as 0in the calculation of Receive mode consumed capacity or charge.

Therefore the total capacity or charge used by the MSUT in one hour isthe sum of the capacity used in both the Receive and Transmit modes:

C _(1 hr) =C _(rx) _(—) _(in) _(—) _(1 hr) +C _(tx) _(—) _(in) _(—)_(1 hr).

The tests may be conducted at different supply voltages and make anaverage if C_(1 hr) is dependent of voltage for improved accuracy.

After determining the available battery capacity, (C_(new)−C_(cutoff)),and the total capacity or charge used by the MSUT in one hour, C_(1 hr),the Standby Time (T_(standby) measured in days) can be determined by:

T _(standby)=(C _(new) −C _(cutoff))/(C _(1 hr)*24 hrs/day).

This test method significantly reduces the time required to complete thestandby time test cases. Each test can be completed in a matter ofhours, instead of days or even weeks.

Alternatively, stand-by time can be calculated using average currentinstead of consumed capacity (or charge) per hour. In fact, since thequantity current is defined as charge per unit time, charge per hour isalso in a dimension of current. Therefore, the only difference is theunit: Amperes (i.e., Coulombs/sec) for the former, and Coulombs/3600 secfor the latter. The terms capacity used in a given time duration, chargeconsumed in a given time duration, and current consumption are usedinterchangeably in this disclosure.

The alternative formula for using average current to compute the averagetransmit capacity or charge consumed by a registration event is:

C _(tx)=1/N Σ _(j=1) ^(N) (C _(j)).

The alternative formula for using average current to compute the averagetransmit current is:

i _(tx) =C _(tx) /T _(tx), where T _(tx) is registration interval.

The alternative formula for using average current to compute the averagereceive current is:

i _(rx)=1/T Σ _(t=0) ^(T) i(t)*Δt, where T is the current measurementinterval.

The alternative formula for using average current to compute thestand-by time is:

T _(standby)=(C _(new) −C _(cutoff))/(i _(tx) +i _(rx)).

Standby time is the length of time the mobile station under test (MSUT)12 can operate in standby mode using its internal battery power.

One embodiment of the test setup is provided herein below for CDMAmobile terminals.

Set the Base Station Emulator according to the test specification. Thefollowing shows one example:

Access parameters:

-   Nominal Power: 0-   Nominal Power Extended: 0-   Initial Power: 0-   Power Step: 3-   Number of Steps: 5-   Max Response Sequence: 2-   Max Request Sequence: 2-   Preamble Size: 3

RSSI=−75 dBm and Pilot Ec/Io=−7 dBm

The Base Station Emulator also has the following default settings:

-   -   SEARCH WIN A=8    -   SEARCH WIN N=8    -   SEARCH WIN R=8    -   Neighbor list includes 7 PN's        The Slot Cycle Index in the MSUT can be set to 2 and the Max        Slot Cycle Index in the base station emulator is set to either 1        or 2 or other values depending on the test case.        If the test case requires QPCH be set to ON, then the QPCH level        is set to −3 dB relative to pilot.

Configuration Change Indicator (CC1) is Off

Deactivate any radio activities other than idle mode operation, anddeactivate any unnecessary applications.

For each Band Class in which the MSUT operates, test the followingscenarios using the above specified settings:

-   Timer Based Registration Period=15 minutes, QPCH ON (SCI=1 & SCI=2)-   Timer Based Registration Period=15 minutes, QPCH OFF (SCI=1 & SCI=2)-   Timer Based Registration Period=30 minutes, QPCH ON (SCI=1 & SCI=2)-   Timer Based Registration Period=30 minutes, QPCH OFF (SCI=1 & SCI=2)

A test procedure was developed to calculate the standby time based onradio shut-off voltage measurements, the total battery capacity betweenthe fully charged battery voltage and the measured radio shut-offvoltage, and multiple current measurements during receive and transmit.The time taken to run a standby time test using this method isconsiderably shorter than measuring the actual standby time of thedevice with a battery.

The standby time test procedure comprises four major parts:

-   1) Determining the battery voltage at which the radio turns off and    determine available capacity of the battery;-   2) Characterizing transmit current measurements (CDMA registration);-   3) Characterizing receive current measurements; and-   4) Calculating the standby time of the MSUT.

Setup equipment and MSUT as shown in FIGS. 1 and 2 and wait for the MSUTto go into idle mode.

FIG. 5 shows in a flowchart an example of a method of determiningstandby time for mobile stations (100), in accordance with an embodimentof the patent disclosure. The method (100) comprises the steps ofmeasuring average current consumption (102) and determining theavailable battery capacity (114). Next, the standby time of the MSUT iscalculated (104) based upon the available battery capacity and measuredaverage current consumption. Other steps may be added to the method(100).

FIG. 6 shows in a flowchart another example of a method of determiningstandby time for mobile stations (110), in accordance with an embodimentof the patent disclosure. The method (110) comprises the steps ofdetermining the battery voltage at which the radio turns off (112) anddetermining the available capacity of the battery (114). Next theaverage current consumption is measured (102) and the standby time ofthe MSUT is calculated (104). Other steps may be added to the method(100).

FIG. 7 shows in a flowchart another example of a method of determiningstandby time for mobile stations (120), in accordance with an embodimentof the patent disclosure.

The method (120) comprises the steps of determining the availablecapacity of the battery (114), measuring transmit current (CDMAregistration) (122) and measuring receive transmit current (124). Nextthe standby time of the MSUT is calculated (104). Other steps may beadded to the method (100).

FIG. 8 shows in an execution and variable flow diagram another exampleof a method of determining standby time for mobile stations (130), inaccordance with an embodiment of the patent disclosure. The method (130)comprises the steps of determining the battery voltage at which theradio turns off (V_(cutoff)) (112) and determining the availablecapacity of the battery (114). Next, transmit current is measured (CDMAregistration) (122). Next, receive current is measured (124). Thetransmit current time measurement t_(tx) _(—) _(in) _(—) _(1 hr) wascalculated in step (122). Finally, the standby time of the MSUT iscalculated (104). For the last step (104), the available capacityC_(new)−C_(cutoff) was calculated in step (114), the transmit currentcapacity measurement C_(tx) _(—) _(in) _(—) _(1 hr) was calculated instep (122) and the receive current measurement C_(rx) _(—) _(in) _(—)_(1 hr) was calculated in step (124). Alternatively, if the availablecapacity and/or the transmit current capacity measurements are known,these may be provided to a module that executes the final step (104).

FIG. 9 shows in a flowchart an example of a method of determining theradio shut off voltage (31), in accordance with an embodiment of thepatent disclosure. The method (31) begins with configuring a testenvironment by setting up a mobile to be set to desired workingconditions (32). Next, wait the sufficient time needed for the MSUTsoftware/hardware to update the battery voltage internally (34). If theratio is still on (36), then decrement the battery voltage (38) andreturn to step (34). Otherwise (36), record the voltage level at whichthe radio turned off (40). Other steps may be added to this method (31).

FIG. 10 shows in a flow chart another example of the process todetermine radio shut off voltage (30), in accordance with an embodimentof the patent disclosure. The process (30) comprises generally of thefollowing steps:

-   -   1) Program the battery simulator to simulate the ESR of the        battery using 4-wire setup (33).    -   2) Set the base station emulator to transmit at desired level in        accordance to test specification, and set all other parameters        in accordance to test specification (35).    -   3) Wait for the MSUT to acquire the signal from the base station        emulator, and enter the slotted mode of operation (37).    -   4) Program the battery simulator unloaded voltage to a small        quantity (for example, 0.2 V) above the expected radio shut-off        voltage, to initiate test (39).    -   5) Wait sufficient time needed for the MSUT software/hardware to        update the battery voltage internally (34).    -   6) Query to see if the radio is still on (36). (This can be        accomplished by trying to force a registration of the MSUT with        the base station emulator).    -   7) Step the battery voltage down by a small quantity (for        example, 0.01V) (38).    -   8) Repeat steps 5 thru 7 until radio turns off    -   9) Record the voltage level at which radio turns off (40).    -   10) Program the battery simulator unloaded voltage to a small        quantity (for example, 0.2 V) above the expected radio shut-off        voltage, turn the radio back on, and repeat steps 5 thru 9 a        number of times to get a reliable average value of radio        shut-off voltage (42).

Once the radio off voltage has been determined, the available capacityof the battery to be used in the standby time calculations iscalculated. To do this, the battery capacity vs. unloaded voltageprofile table is characterized.

To characterize the transmit current measurements (122), the basestation emulator is set with the timer based registration to “on” andthe base station emulator is programmed to have the MSUT 12 registerperiodically (preferably shorter than the actual registration intervalwhen used in a CDMA network, for example, every 12.1 to 30 seconds),disabling all other types of registrations except power up registration,and set the base station emulator output power to the values as definedin the test specification (e.g., −75 dBm) with path loss accounted for.The setting to have MSUT 12 register every 12.1 to 30 seconds is notrelated to the network configuration under which the standby time to betested and is used only to reduce test time.

Using the battery simulator 18, the output voltage is set to a desiredvalue, e.g., the nominal battery voltage, and a sampling interval andarray size are selected which will have a long enough window to be ableto extract the sub-array of the measured battery current to cover theentire transmit activity from start of the transmitter warm-up for theregistration to its end (e.g., download 4096 data points from batterysimulator 66321D at sampling interval of 4 ms will ensure a window largeenough to capture transmit and back to receive). The battery simulatorcan buffer pre-trigger current measurement data points, which willensure capturing current data prior to the triggering point and covers atime span from receive to transmit back to receive modes. See FIG. 3 asan example.

FIG. 11 shows in a flowchart an example of a method of measuringtransmit current (122), in accordance with an embodiment of the patentdisclosure. The method (122) comprises the steps of collecting asufficient time span of current measurement data points (202). Next, themeasurements relating to the time the transmitter is turned on areextracted (204). Finally, the capacity used (C_(j)) and time duration(t_(j)) of each transmit event are calculated (206). Other steps may beadded to this method (122).

FIG. 12 shows in a flowchart another example of a method of measuringtransmit current (123) using the battery simulator 18, in accordancewith an embodiment of the patent disclosure. The method (123) comprisesgenerally of the following steps:

-   -   1) Trigger the simulator to start collecting current measurement        data points when a transmit activity is detected (201) (e.g., by        a threshold set for current level exceeding the current        consumption level for receiver only operation, such as 250 mA).    -   2) Collect the sufficient time span of current measurement data        points from battery simulator (202) (66321D will be able to        download an array of 4096 data points).    -   3) Extract, from the data array, the sub-array for the portion        of time the transmitter is turned on (204).    -   4) Knowing the current at each data point in the sub-array        extracted, allows the calculation of the capacity used (C_(j))        and time duration (t_(j)) of each transmit event (206):

C _(j)=(Σ_(k=0) ^(m) (i _(k)))*Δt; and

t_(j)=m*Δt,

-   -   where k=0 is the first point of the transmit activity, m is the        last point of the transmit activity, and Δt is the sample        interval.    -   5) Repeat 1) through 5) to record N transmit measurements        (desirably N>100).    -   6) Determine the average capacity used by transmit events in one        hour (C_(tx) _(—) _(in) _(—) _(1 hr)), and the time spent in        transmitting events during one hour (t_(tx) _(—) _(in) _(—)        _(1 hr)) (208).

C _(tx) _(—) _(in) _(—) _(1 hr)=(Σ_(j=1) ^(N) (C _(j)))*(M/N); and

t _(tx) _(—) _(in) _(—) _(1 hr)=(Σ_(j=1) ^(N) (t _(j)))*(M/N),

-   -   where N is the total number of transmit events measured; and    -   where M is the number of registrations per hour based on network        registration period configuration for which the standby time        needs to be determined (M may not be an integer).

FIG. 13 shows in a flowchart an example of a method of measuring receivecurrent (124), in accordance with an embodiment of the patentdisclosure. The method (124) begins with configuring the base stationemulator to disable timer based registration and all other typesregistrations except the power up registration (222). Next, the receivecurrent array of the MSUT is measured segment by segment using asampling interval small enough to capture all current activities (224).Preferably, this sampling interval is no larger than 1 ms. Other stepsmay be added to this method (124).

FIG. 14 shows in a flowchart another example of a method of measuringreceive current (125), in accordance with an embodiment of the patentdisclosure. The following receive current measurements are performed foreach test condition being tested (such as SCI values, quick pagingsettings). Again, using the battery simulator,

-   -   1) Configure the base station emulator to disable timer based        registration and all other types registrations except the power        up registration (222).    -   2) Measure the receive current array of MSUT segment by segment        using a sampling interval small enough to capture all current        activities (224). Preferably, this sampling interval is no        larger than 1 ms.    -   3) Record multiple receive current segments (226) (e.g., greater        than 100).    -   4) For each segment, post process the current measurement data        array (228), calculate the mean current value of each receive        segment (230), and further calculate the mean over all the        segments measured (232), denote it i_(rx).    -   5) Determine the capacity used while in receive mode for 1 hour        of MSUT operation (234):        -   In 1 hour operation, the amount of time spent in receive            mode is simply the amount of time the MSUT is not in            transmit mode, which is (1−t_(tx) _(—) _(in) _(—) _(1 hr))            hour, thus the capacity used for 1 hour by receive mode:

C _(rx in 1 hr)=(i _(rx)*(1−t _(tx in 1 hr))).

The capacity used in one hour for both transmit and receive activitiesis known, thus the total capacity used by the MSUT in one hour is:

C _(1 hr) =C _(rx) _(—) _(in) _(—) _(1 hr) +C _(tx) _(—) _(in) _(—)_(1 hr).

Using the available battery capacity determined as described previously,the standby time in hours can then be determined (104) by:

T _(standby)=(C _(new) −C _(cutoff))/(C _(1 hr)).

The system and methods according to the present disclosure may beimplemented by any hardware, software or a combination of hardware andsoftware having the above described functions. The software code, eitherin its entirety or a part thereof, may be stored in a computer readablememory. Further, a computer data signal representing the software codewhich may be embedded in a carrier wave may be transmitted via acommunication network. Such a computer readable memory and a computerdata signal are also within the scope of the present disclosure, as wellas the hardware, software and the combination thereof.

While particular embodiments of the patent disclosure have been shownand described, changes and modifications may be made to such embodimentswithout departing from the true scope of the patent disclosure.

1. A method, comprising: coupling a battery simulator to a mobilestation, the battery simulator configured to provide the mobile stationwith a simulated battery voltage; measuring, for a predetermined timeperiod, a plurality of current measurement data points of the mobilestation in standby mode; calculating, from the plurality of currentmeasurement data points, an average current consumption associated withthe mobile station in the standby mode; determining an actual batterycapacity of a battery for the mobile station; and determining a standbytime of the mobile station based on the average current consumption andthe actual battery capacity.
 2. The method of claim 1, wherein thepredetermined time period is less than the standby time.
 3. The methodof claim 1, wherein the average current consumption measured is anaverage value determined over the predetermined time period.
 4. Themethod of claim 1, further comprising: determining a battery cut offvoltage for the mobile station.
 5. The method of claim 4, whereindetermining the actual battery capacity comprises: deriving the actualbattery capacity in dependence upon the battery cut off voltage of themobile station.
 6. The method of claim 4, wherein the actual batterycapacity is an amount of discharge from a fully charged battery to thebattery cut off voltage.
 7. The method of claim 6, further comprising:fully-charging the battery; and determining the fully-charged voltage ofthe battery after being fully charged, and wherein the actual batterycapacity is determined based on a difference between the fully-chargedvoltage and the battery cut off voltage.
 8. The method of claim 4,wherein the battery cut off voltage for the mobile station is determinedby stepping down the simulated battery voltage until a radio of themobile station turns off.
 9. The method of claim 4, wherein thedetermining the battery cut off voltage comprises: adjusting thesimulated battery voltage provided to the mobile station; determining avoltage level at which a mobile station radio turns off as the batterycut off voltage.
 10. A system comprising: a battery simulator coupled toa mobile station, the battery simulator configured to provide the mobilestation with a simulated battery voltage; a computer configured tomeasure, for a predetermined time period, a plurality of currentmeasurement data points of the mobile station in standby mode;calculate, from the plurality of current measurement data points, anaverage current consumption associated with the mobile station in thestandby mode; determine an actual battery capacity of a battery for themobile station; and determine a standby time of the mobile station basedon the average current consumption and the actual battery capacity. 11.The system of claim 10, wherein the predetermined time period is lessthan the standby time.
 12. The system of claim 10, wherein the averagecurrent consumption measured is an average value determined over thepredetermined time period.
 13. The system of claim 10, wherein thecomputer is configured to determine a battery cut off voltage for themobile station.
 14. The system of claim 13, wherein the computer isconfigured to derive the actual battery capacity in dependence upon thebattery cut off voltage of the mobile station.
 15. The system of claim13, wherein the actual battery capacity is an amount of discharge from afully charged battery to the battery cut off voltage.
 16. The system ofclaim 15, wherein the computer is configured to determine afully-charged voltage of the battery after being fully charged, andwherein the actual battery capacity is determined based on a differencebetween the fully-charged voltage and the battery cut off voltage. 17.The system of claim 13, wherein the battery cut off voltage for themobile station is determined by stepping down the simulated batteryvoltage until a radio of the mobile station turns off.
 18. The system ofclaim 13, wherein the computer is configured to adjust the simulatedbattery voltage provided to the mobile station; and determine a voltagelevel at which a mobile station radio turns off as the battery cut offvoltage.
 19. A computer-readable medium configured with code executableby a computer to cause the computer to: measure, for a predeterminedtime period, a plurality of current measurement data points of a mobilestation in standby mode; calculate, from the plurality of currentmeasurement data points, an average current consumption associated withthe mobile station in the standby mode; determine an actual batterycapacity of a battery for the mobile station; and determine a standbytime of the mobile station based on the average current consumption andthe actual battery capacity, wherein the mobile station is coupled to abattery simulator, the battery simulator configured to provide themobile station with a simulated battery voltage.
 20. Thecomputer-readable medium of claim 19, wherein the predetermined timeperiod is less than the standby time.
 21. The computer-readable mediumof claim 19, wherein the average current consumption measured is anaverage value determined over the predetermined time period.
 22. Thecomputer-readable medium of claim 19, wherein the code further causesthe computer to: determine a battery cut off voltage for the mobilestation.
 23. The computer-readable medium of claim 22, wherein the codefurther causes the computer to: derive the actual battery capacity independence upon the battery cut off voltage of the mobile station. 24.The computer-readable medium of claim 22, wherein the actual batterycapacity is an amount of discharge from a fully charged battery to thebattery cut off voltage.
 25. The computer-readable medium of claim 24,wherein the code further causes the computer to determine afully-charged voltage of the battery after being fully charged, andwherein the actual battery capacity is determined based on a differencebetween the fully-charged voltage and the battery cut off voltage. 26.The computer-readable medium of claim 22, wherein the battery cut offvoltage for the mobile station is determined by stepping down thesimulated battery voltage until a radio of the mobile station turns off.27. The computer-readable medium of claim 22, wherein the code furthercauses the computer to: adjust the simulated battery voltage provided tothe mobile station; determine a voltage level at which a mobile stationradio turns off as the battery cut off voltage.